A Letter of Medical Necessity (LMN) is a document completed by a licensed healthcare provider that explains why a specific product or service is medically necessary to treat a diagnosed medical condition.
Some expenses that are generally considered wellness or personal expenses may become eligible for reimbursement under a pre-tax benefit account when they are recommended to treat a diagnosed medical condition. In these cases, an LMN helps document the medical necessity of the expense and supports its eligibility for reimbursement.
What should be included in an LMN?
A valid Letter of Medical Necessity should include:
The patient's name
The healthcare provider's name and credentials
The patient's diagnosed medical condition
A recommendation for the specific product or service needed to treat that condition
The expected duration of treatment (or a statement that the treatment is ongoing, if applicable)
The healthcare provider's signature and the date the letter was signed
Important: Whenever possible, your healthcare provider should include the expected duration of treatment. If no duration is provided, the LMN is generally considered valid for one year from the date it was signed. After that time, a new LMN may be required if you continue submitting claims for the same expense.
Most healthcare providers are familiar with Letters of Medical Necessity and can provide one upon request.
When do I need to submit an LMN?
If your expense requires proof of medical necessity, Benepass will notify you during the claims review process and ask you to upload an LMN before your claim can be approved.
If you already know your purchase requires an LMN, we recommend uploading it when you submit your claim along with your receipt or other required supporting documentation. Providing all required documentation upfront helps us review your claim more quickly.
Does an LMN guarantee reimbursement?
No. An LMN helps demonstrate that an expense is medically necessary, but reimbursement is still subject to your benefit's eligibility rules, IRS requirements (for pre-tax benefits), and your employer's benefit policy. Additional documentation may be requested if needed to complete the review.
Sample Letter of Medical Necessity
If your healthcare provider would like guidance on what to include, you can share this sample Letter of Medical Necessity template:
Note: A Social Security number is not required for a Letter of Medical Necessity to be considered valid.